The number of molecules present in `1cm^(3)` of an ideal gas at STP is called …………..and its value is…………… .

Explanation

To solve the question, we need to identify what is being asked and provide the correct terminology and value associated with the number of molecules in 1 cm³ of an ideal gas at standard temperature and pressure (STP).

### Step-by-Step Solution:

1. **Understanding STP**:
- Standard Temperature and Pressure (STP) is defined as a temperature of 0 degrees Celsius (273.15 K) and a pressure of 1 atmosphere (atm).

2. **Ideal Gas Behavior**:
...